In our most trying times, I think sometimes we are prone to waver in our faith.
The Jewish believers at this time were being persecuted and run out of their homes. It was a difficult time for them.
They were thinking that if we just go back to doing the law, all this will end.
Maybe the other Jews were right, that we have to obey the law in order for God to have favor on us.
In other words, it depends on our behavior, not on what Jesus did.
The writer is saying-don’t waver. But hold tightly to the hope you say you have. Hold on to what you know to be true.